Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles.
The present study reports some fascinating results of Hantzsch's [3 + 2] cyclic condensation of α-bromo-1,3-diketones, a tri-electrophilic synthon generated in situ by bromination of 1,3-diketones using the mild brominating reagent NBS with trinucleophilic N-substituted thioureas. Interestingly...
| Autores: | , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/115833 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/115833 |
| Access Level: | acceso abierto |
| Palabra clave: | 23 32 576 Heterocyclo Regiselectivity Substituted 2-aminothiazoles Crystallography Ciencias 2303 Química Inorgánica |
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Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles.Aggarwal, RanjanaSharma, ShilpaSanz, DionisiaClaramunt, Rosa M.Delgado, PatriciaTorralba, M. CarmenTorralba Martínez, María Del Carmen2332576HeterocycloRegiselectivitySubstituted 2-aminothiazolesCrystallographyCiencias2303 Química Inorgánica2303 Química InorgánicaThe present study reports some fascinating results of Hantzsch's [3 + 2] cyclic condensation of α-bromo-1,3-diketones, a tri-electrophilic synthon generated in situ by bromination of 1,3-diketones using the mild brominating reagent NBS with trinucleophilic N-substituted thioureas. Interestingly, out of a total of 20 combinations, 10 resulted in the exclusive formation of the desired 2-(N-arylamino)-5-acyl-4-methylthiazoles regioselectively, seven led to the formation of unexpected 2-(N-acylimino)-3-N-aryl-4-methylthiazoles through an interesting C–N acyl migration, and three furnished a mixture consisting of both products. The regioselectivity pattern of the two products may be attributed to a greater electrophilicity of the carbonyl carbon of the acetyl group than that of the acyl group towards both nitrogens of thiourea. The structures of the thiazole derivatives were unambiguously assigned using 1H-NMR, 13C-NMR, and rigorous heteronuclear 2D-NMR [(1H–13C) HMQC and (1H–13C) HMBC] spectroscopic techniques. The outcomes of the spectroscopic experiments were further concurred through X-ray crystallographic studies, and a plausible mechanism for acyl migration was proposed for the formation of the unexpected rearranged product.Royal Society of ChemistryUniversidad Complutense de Madrid20242024-11-0820242024-11-08journal articlehttp://purl.org/coar/resource_type/c_6501VoRhttp://purl.org/coar/version/c_970fb48d4fbd8a85info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/115833reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2Attribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/1158332026-06-02T12:44:21Z |
| dc.title.none.fl_str_mv |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. |
| title |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. |
| spellingShingle |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. Aggarwal, Ranjana 23 32 576 Heterocyclo Regiselectivity Substituted 2-aminothiazoles Crystallography Ciencias 2303 Química Inorgánica 2303 Química Inorgánica |
| title_short |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. |
| title_full |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. |
| title_fullStr |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. |
| title_full_unstemmed |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. |
| title_sort |
Reaction of unsymmetrical -bromo-1,3-diketones with N-substituted thioureas: regioselective access to 2-(N-arylamino)-5-acyl-4-methylthiazoles and/or rearranged 2-(N-acylimino)-3-N-aryl-4-methylthiazoles. |
| dc.creator.none.fl_str_mv |
Aggarwal, Ranjana Sharma, Shilpa Sanz, Dionisia Claramunt, Rosa M. Delgado, Patricia Torralba, M. Carmen Torralba Martínez, María Del Carmen |
| author |
Aggarwal, Ranjana |
| author_facet |
Aggarwal, Ranjana Sharma, Shilpa Sanz, Dionisia Claramunt, Rosa M. Delgado, Patricia Torralba, M. Carmen Torralba Martínez, María Del Carmen |
| author_role |
author |
| author2 |
Sharma, Shilpa Sanz, Dionisia Claramunt, Rosa M. Delgado, Patricia Torralba, M. Carmen Torralba Martínez, María Del Carmen |
| author2_role |
author author author author author author |
| dc.contributor.none.fl_str_mv |
Universidad Complutense de Madrid |
| dc.subject.none.fl_str_mv |
23 32 576 Heterocyclo Regiselectivity Substituted 2-aminothiazoles Crystallography Ciencias 2303 Química Inorgánica 2303 Química Inorgánica |
| topic |
23 32 576 Heterocyclo Regiselectivity Substituted 2-aminothiazoles Crystallography Ciencias 2303 Química Inorgánica 2303 Química Inorgánica |
| description |
The present study reports some fascinating results of Hantzsch's [3 + 2] cyclic condensation of α-bromo-1,3-diketones, a tri-electrophilic synthon generated in situ by bromination of 1,3-diketones using the mild brominating reagent NBS with trinucleophilic N-substituted thioureas. Interestingly, out of a total of 20 combinations, 10 resulted in the exclusive formation of the desired 2-(N-arylamino)-5-acyl-4-methylthiazoles regioselectively, seven led to the formation of unexpected 2-(N-acylimino)-3-N-aryl-4-methylthiazoles through an interesting C–N acyl migration, and three furnished a mixture consisting of both products. The regioselectivity pattern of the two products may be attributed to a greater electrophilicity of the carbonyl carbon of the acetyl group than that of the acyl group towards both nitrogens of thiourea. The structures of the thiazole derivatives were unambiguously assigned using 1H-NMR, 13C-NMR, and rigorous heteronuclear 2D-NMR [(1H–13C) HMQC and (1H–13C) HMBC] spectroscopic techniques. The outcomes of the spectroscopic experiments were further concurred through X-ray crystallographic studies, and a plausible mechanism for acyl migration was proposed for the formation of the unexpected rearranged product. |
| publishDate |
2024 |
| dc.date.none.fl_str_mv |
2024 2024-11-08 2024 2024-11-08 |
| dc.type.none.fl_str_mv |
journal article http://purl.org/coar/resource_type/c_6501 VoR http://purl.org/coar/version/c_970fb48d4fbd8a85 |
| dc.type.openaire.fl_str_mv |
info:eu-repo/semantics/article |
| format |
article |
| dc.identifier.none.fl_str_mv |
https://hdl.handle.net/20.500.14352/115833 |
| url |
https://hdl.handle.net/20.500.14352/115833 |
| dc.language.none.fl_str_mv |
Inglés eng |
| language_invalid_str_mv |
Inglés |
| language |
eng |
| dc.rights.none.fl_str_mv |
open access http://purl.org/coar/access_right/c_abf2 Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| dc.rights.openaire.fl_str_mv |
info:eu-repo/semantics/openAccess |
| rights_invalid_str_mv |
open access http://purl.org/coar/access_right/c_abf2 Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
| eu_rights_str_mv |
openAccess |
| dc.format.none.fl_str_mv |
application/pdf |
| dc.publisher.none.fl_str_mv |
Royal Society of Chemistry |
| publisher.none.fl_str_mv |
Royal Society of Chemistry |
| dc.source.none.fl_str_mv |
reponame:Docta Complutense instname:Universidad Complutense de Madrid (UCM) |
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Universidad Complutense de Madrid (UCM) |
| reponame_str |
Docta Complutense |
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Docta Complutense |
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| repository.mail.fl_str_mv |
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1869421958835208192 |
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15,81155 |